java.net
Interfaces 
ContentHandlerFactory
FileNameMap
SocketImplFactory
SocketOptions
URLStreamHandlerFactory
Classes 
Authenticator
ContentHandler
DatagramPacket
DatagramSocket
DatagramSocketImpl
HttpURLConnection
InetAddress
JarURLConnection
MulticastSocket
NetPermission
PasswordAuthentication
ServerSocket
Socket
SocketImpl
SocketPermission
URL
URLClassLoader
URLConnection
URLDecoder
URLEncoder
URLStreamHandler
Exceptions 
BindException
ConnectException
MalformedURLException
NoRouteToHostException
ProtocolException
SocketException
UnknownHostException
UnknownServiceException